diff --git a/frontend/src/hooks/useMediaStreamASR.ts b/frontend/src/hooks/useMediaStreamASR.ts
index 31766b0..38c3283 100644
--- a/frontend/src/hooks/useMediaStreamASR.ts
+++ b/frontend/src/hooks/useMediaStreamASR.ts
@@ -28,6 +28,7 @@ export function useMediaStreamASR({ wsUrl }: UseMediaStreamASRProps): UseMediaSt
   const wsRef = useRef<WebSocket | null>(null)
   const audioContextRef = useRef<AudioContext | null>(null)
   const processorRef = useRef<ScriptProcessorNode | null>(null)
+  const gainNodeRef = useRef<GainNode | null>(null)
   const sourceRef = useRef<MediaStreamAudioSourceNode | null>(null)
   const streamRef = useRef<MediaStream | null>(null)
   const isStreamingRef = useRef(false)
@@ -63,8 +64,10 @@ export function useMediaStreamASR({ wsUrl }: UseMediaStreamASRProps): UseMediaSt
     }
 
     processorRef.current?.disconnect()
+    gainNodeRef.current?.disconnect()
     sourceRef.current?.disconnect()
     processorRef.current = null
+    gainNodeRef.current = null
     sourceRef.current = null
 
     if (wsRef.current) {
@@ -114,18 +117,22 @@ export function useMediaStreamASR({ wsUrl }: UseMediaStreamASRProps): UseMediaSt
       const processor = audioContext.createScriptProcessor(4096, 1, 1)
       processorRef.current = processor
 
-      // onaudioprocess — mirrors useVideoASR lines 126-132 exactly
+      // Zero-gain node mutes audio output to prevent echo/feedback. The processor
+      // must remain in the graph (connected to destination) so onaudioprocess fires.
+      const zeroGain = audioContext.createGain()
+      zeroGain.gain.value = 0
+      gainNodeRef.current = zeroGain
+
       processor.onaudioprocess = (e) => {
         const float32Data = e.inputBuffer.getChannelData(0)
-        const outputData = e.outputBuffer.getChannelData(0)
-        outputData.set(float32Data)
         if (!isStreamingRef.current) return
         if (!wsRef.current || wsRef.current.readyState !== WebSocket.OPEN) return
         wsRef.current.send(float32Data.buffer)
       }
 
       source.connect(processor)
-      processor.connect(audioContext.destination)
+      processor.connect(zeroGain)
+      zeroGain.connect(audioContext.destination)
 
       const ws = new WebSocket(wsUrl)
       wsRef.current = ws
@@ -181,6 +188,7 @@ export function useMediaStreamASR({ wsUrl }: UseMediaStreamASRProps): UseMediaSt
         })
       }
       processorRef.current?.disconnect()
+      gainNodeRef.current?.disconnect()
       sourceRef.current?.disconnect()
       wsRef.current?.close()
       audioContextRef.current?.close()